Cardiac disease is generally described as congenital or acquired. There are significant physiological changes to the cardiovascular system in pregnancy (see Chapter 5) and obstetric patients with pre‐existing cardiac disease may suffer an exacerbation of symptoms as a result. In the period from 2011 to 2013, approximately 23% of all maternal deaths in the UK (49 in total) resulted from cardiac disease (MBRRACE‐UK, 2015a), making this the leading indirect cause of death. The majority of these deaths were related to acquired cardiac diseases, the most common of which were classified as sudden adult death syndrome (SADS) (25%), aortic dissection (20%) and peripartum cardiomyopathy (12%); 22% died from other cardiac conditions. Acute coronary syndromes accounted for 20% of all cardiac‐related deaths. The 2013–15 MBRRACE‐UK report showed a similar trend, noting that cardiac disease remains the leading cause of indirect maternal death during or up to 6 weeks after the end of pregnancy with a rate of 2.34 per 100 000 maternities.

Risk factors

Pre‐existing cardiac disease

Obesity

Smoking

Family history

Diabetes

Hypertension

Hypercholesterolaemia

Maternal age over 35 years

Marfan’s syndrome

Rheumatic fever – a particular risk in patients originating from areas with a higher prevalence

Diagnosis

The symptoms of an acute coronary syndrome (ACS) are the same during pregnancy as they are for any other patient, although distinguishing an acute cardiac cause for chest pain from symptoms related to gastro‐oesophageal reflux (common in pregnancy) can be difficult. It should be noted that in normal pregnancy there may be some increased dyspnoea, but radiating, crushing pain is always a ‘red flag’. The practitioner must have a high index of suspicion and perform a 12‐lead ECG before admitting the woman to an appropriate emergency department or centre providing primary percutaneous coronary intervention (PCI).

It must be noted that intermittent episodes of simple arrhythmia (e.g. supraventricular tachycardia or ectopic beats) are common in pregnancy and often symptoms such as palpitations do not cause significant compromise. However, a pre‐hospital call to a collapsed woman where the ECG demonstrates an arrhythmia has to be construed as an emergency and should be treated as per normal guidelines and referred for cardiac assessment.

Acute cardiogenic pulmonary oedema occurs rarely during pregnancy and will usually present with typical findings including shortness of breath, increasing nocturnal dyspnea and orthopnoea, and coughing up pink frothy sputum.

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Aortic dissection should always be considered in pregnant and postpartum women with atypical chest pain (particularly if the pain is interscapular in association with hypertension).

Pre‐hospital management

Pain, acute shortness of breath or any systemic sign or symptom that compromises the patient’s haemodynamic status should be considered a pre‐hospital emergency. A full ABCDEFG assessment will assist in determining the nature of the problem. Remember that this is potentially a life‐threatening emergency for the mother and baby.

Assess a full set of baseline observations, including blood glucose level and record a 12‐lead ECG.

Initiate transfer to the most appropriate hospital according to local guidelines, based on their ECG. If an ST‐elevation myocardial infarction has been diagnosed consider taking the patient directly to a unit capable of providing primary PCI.

Provide a pre‐alert call to the receiving hospital.

Insert a large‐bore cannula en route (do NOT delay on scene to do this).

Provide intravenous morphine for moderate to severe pain with an antiemetic (e.g. cyclizine or ondansetron) if necessary.

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Pre‐hospital thrombolysis is contraindicated in pregnancy.

10.2 Epilepsy in pregnancy

Definition

This is defined as a continuing tendency to have seizures. Epilepsy manifests itself through a wide range of signs and symptoms. These range from a tremor in one limb through to a whole‐body convulsion, or from an unpleasant taste in the patient’s mouth to unconsciousness. On average, one person in 170 in the UK is being treated for epilepsy. It is estimated that the risk of premature death within this group is 2–3 times higher than in the general population (Hanna et al., 2002).

Convulsions are predominantly classified as partial or generalised. Partial (focal) convulsions can be further subdivided as simple or complex and it is rare for either to compromise the pre‐hospital patient in a way that requires immediate intervention. Generalised convulsions can also be subdivided and are referred to as either an absence or as a tonic‐clonic episode. The latter will concern the pre‐hospital practitioner in pregnancy as it can be impossible to differentiate from eclampsia. Eight maternal deaths occurred in the UK as a result of epilepsy in the period from 2013 to 2015 (MBRRACE‐UK, 2017).

Risk factors

Poor compliance

Sleep deprivation

Hyperemesis

Stopping anticonvulsant medication during pregnancy

Unstable epilepsy

Reduced efficacy of medications through altered pharmacokinetics (caused by changes in absorption or dilution and hyperemesis) in pregnancy, which can exacerbate pre‐existing epilepsy

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Pregnant women with epilepsy often face additional physical, mental health or social problems. As with all women with these types of problems, additional effort should be taken to ensure they have access to the care they need. This should take into account interpersonal dynamics which may be challenging, provide properly trained interpreters where necessary, and link up with agencies outside the health service (including prisons, probation services, police forces and social services).

Diagnosis

A convulsing patient may or may not have epilepsy. Most patients you are called to will be postictal by the time you arrive. A patient who is convulsing continuously for more than 5 minutes, or who has repeated convulsions without recovering consciousness in between, is considered to be in status epilepticus. It should be remembered, however, that a patient who is not known to be epileptic should be managed using eclampsia guidelines (see Chapter 9). Vasovagal attacks are common in pregnancy and may lead to generalised convulsions. However, even if there is a strong suspicion that a convulsion may have resulted from a relatively benign cause, such as a vasovagal episode, the patient will still need a full hospital assessment to exclude eclampsia and other significant pathologies.

Other less common causes of convulsions during pregnancy include:

Drug or alcohol withdrawal

Dysrhythmias

Pseudoepilepsy

Hypoglycaemia

Thrombotic thrombocytopenic purpura

Cerebral infarction

Hypocalcaemia

Gestational epilepsy (convulsions confined to pregnancy)

Meningitis

Cerebral vein thrombosis

A thorough ABCDEFG assessment may help identify the underlying cause of the convulsion. Getting to the point quickly is essential; this will help pinpoint the cause and the associated treatment, for instance assessing the blood glucose level and the urine for proteinuria.

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A fitting obstetric patient who is not known to be epileptic should be managed using eclampsia guidelines.

Pre‐hospital management

A convulsing obstetric patient represents a time‐critical emergency. Whilst time on scene should be minimised, it is appropriate to stabilise your patient prior to moving her, when conditions allow. It is preferable to attempt to control the convulsion before handling and moving the patient; moving a convulsing obstetric patient is particularly challenging.

Manage the ABCs as outlined before.

Treat for eclampsia if the patient is not known to have epilepsy (see Chapter 7). Be aware that eclampsia can also occur in a patient who has epilepsy – treat for eclampsia if in any doubt.

If the patient is still convulsing, give a benzodiazepine to stop the seizure. Suitable options include diazepam IV/PR (10–20 mg titrated to effect), buccal midazolam (10 mg) or lorazepam IV (up to 4 mg).

A blood glucose test should be performed; if the reading is low, the patient should be managed in accordance with the treatment of hypoglycaemia guidelines.

If the convulsion cannot be controlled in the pre‐hospital environment the patient will need rapid removal to hospital.

An obstetric patient who has had a seizure, even if they are known to have epilepsy and have fully recovered, should be transported to hospital for a full assessment, as significant pathologies cannot safely be excluded at the scene.

10.3 Venous thromboembolism in pregnancy

Definition

A venous thromboembolism (VTE) is a thrombus (blood clot) in part of the circulatory system which has the potential to become detached. This clot can then be moved by the blood through the vessels and lodged in another part of the system – the location determining the nature and severity of the symptoms. The thrombus usually originates in the deep veins of the legs or pelvis and is referred to as a deep vein thrombosis (DVT). If it is carried to the pulmonary vasculature it causes a pulmonary embolism (PE). Ileofemoral thrombi are the most common form of DVT and also are more likely to embolise. VTE is estimated to be up to ten times more common in pregnant women than in non‐pregnant women of the same age (RCOG, 2001). Thromboembolism in the form of either PE or cerebral venous thrombosis has been found to be the highest direct cause of maternal death in the UK (MBRRACE‐UK, 2017). It is predicted that many of these deaths could be avoided with improved recognition of risk factors, greater and earlier appreciation of the signs and symptoms, and earlier implementation of either prophylaxis or treatment.

Risk factors

Age (particularly over 35 years)

Obesity (body mass index greater than 30 kg/m2 either pre or early pregnancy)

Long haul travel; this is not solely confined to air travel and includes prolonged immobility in association with car, bus or rail travel

Operative delivery; one‐half of all deaths from PE followed delivery by caesarean section (MBRRACE‐UK, 2015a)

Instrumental vaginal delivery

Prolonged labour (greater than 12 hours)

Surgical procedures in pregnancy or puerperium

Prolonged time in lithotomy

Diagnosis

The location of the embolism will determine the nature and severity of the signs and symptoms. A DVT manifests as pain, swelling and tenderness in the calf muscle although lower abdominal pain may be the only presenting symptom in ileofemoral DVT.

The most common findings in PE are tachypnoea, dyspnoea, pleuritic chest pain, cough and haemoptysis. Clinical evidence of DVT is rarely found in patients with PE. Tachycardia may be the only sign of a PE, or there may be no abnormal physical signs at all. A massive PE may present with signs of cyanosis, hypotension, sudden collapse or cardiorespiratory arrest.

Local policies should be in place for the investigation of possible VTE once the patient reaches hospital.

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Although tachypnoea, dyspnoea and leg pain are commonly found in pregnancy they should be investigated in order to exclude VTE.

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The risk of VTE is as high in the first trimester as it is in late pregnancy.

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If presented with a haemodynamically unstable patient with sudden onset of tachypnoea, dyspnoea, chest pain and tachycardia, a PE should be considered in your differential diagnosis.

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The commonest ECG finding in a patient with a PE is sinus tachycardia. However, patients presenting with massive PE may occasionally show the following ‘textbook’ ECG changes:

S wave in lead I

Q wave in lead III

T wave inversion in lead III

Pre‐hospital management

A suspected PE with haemodynamic instability is a time‐critical, life‐threatening emergency requiring rapid transfer to hospital.

While performing an obstetric primary survey and obtaining an obstetric history also carry out the following:

Assess and manage the ABCs as outlined before.

Start transportation without delay to the nearest appropriate hospital.

Provide a pre‐alert message to the receiving hospital unit.

Obtain IV access en route.

10.4 Diabetes in pregnancy

Definition

Diabetes is the most common pre‐existing medical disorder complicating pregnancy in the UK, with approximately one pregnant woman in every 250 having pre‐existing diabetes (CEMACH, 2007c). Patients with pre‐existing diabetes may be of Type I or Type II. In maternity care, Type II diabetes is becoming much more common as it is related to obesity; it may present for the first time in pregnancy.

Gestational diabetes is diabetes appearing in pregnancy for the first time and may require diet, metformin or insulin, or a combination of treatments. It resolves after delivery. It is estimated to develop in up to 12% of women (DoH, 2001).

Normoglycaemia (4–8 mmol/l in pregnancy) is the basis of sound pregnancy care. Unfortunately, diabetes becomes more difficult to manage during pregnancy due to changes in physiology and metabolism. As insulin resistance increases due to the effect of placental hormones, insulin requirements often double during pregnancy in Type I diabetes. Recent studies also demonstrate that many women enter pregnancy with poor glycaemic control and half of all diabetic obstetric patients suffer recurrent hypoglycaemia. Severe hypoglycaemia requiring emergency treatment is a relatively common complication of diabetes in pregnancy (CEMACH, 2007c). Diabetic ketoacidosis (DKA) is relatively rare in pregnancy but when it does occur, it requires prompt and skilled management to avert a poor outcome. Fortunately, maternal deaths from diabetes remain rare (CEMACH, 2007a).

Risk factors

Obesity

Family history

Ethnic group – especially if from the Indian subcontinent

Previous impaired glucose tolerance or gestational diabetes

Advanced maternal age (more than 40 years)

Diagnosis

De novo (new) diabetes

Thirst

Polyuria

Weight loss

Persistent heavy glycosuria

Polyhydramnios

Increased fetal growth

Raised random blood sugar

Features of DKA (see following)

Hypoglycaemia

This may occur with any type of diabetes for which the patient is receiving medication, which may be oral hypoglaemic agents and/or insulin. It does not occur in patients whose diabetes is controlled purely by diet.

Pallor

Sweating

Malaise

Shaking/shivering

Blood sugar below 4 mmol/l

Altered mental state

Reducing level of consciousness

Diabetic ketoacidosis

This is usually in association with a concurrent illness, infection (a urinary tract infection is common) or poor diabetic control (sometimes due to poor compliance). Note not all symptoms may be present.

Polyuria

Polydipsia

Nausea and vomiting

Abdominal cramps

Dehydration

Shivering

Hyperglycaemia

Altered mental state

Falling level of consciousness

Dysrhythmia

Ketotic breath

Ketonuria

Raised serum lactate

Kussmaul’s respirations

Pregnancy complications associated with diabetes

Women with either pre‐existing diabetes or gestational diabetes are at increased risk of many complications of pregnancy. These include: